PascalSCADA development: What is the best tag management model?

After use the PascalSCADA in some personal projects, I found some obstacles. The biggest one is related with the number of tags declared into the HMI/SCADA project being developed. Actually the Lazarus can handle forms or datamodules with a small number components inserted into, but this number can’t be bigger than
two thousand of components (or tags if you want). Delphi I’ll not comment. This tag management model was born in a time that I don’t know that Lazarus and Delphi can’t handle with a huge number of components. So to workaround this limit of the current PascalSCADA version, you need to split the set of tags in several forms/datamodules or to create the tags in runtime, what need some skills.

This is what I need to start a new PascalSCADA version. Actually the progress of this new version is hosted at

This version uses the most modern features available on the recent Lazarus and FreePascal versions. It will be a full modular version, in other words, you will only install the desired packages. The translation will be easier through the PO files, native from Lazarus. The multithread system can now specify which processor core each thread will run over. The interface of tag control and security was splitted, the opposite of what is today.  A new protocol design will make easy the OPC implementation. And major part of default controls of Lazarus will have a class with security enabled, and these controls will be the base of the new PascalSCADA HCl, that will be much larger and better, able to  protect any kind of application, including  database applications.

But the question which I dedicated myself to write this post is: For you, what’s the best tag management models that exists on the market today? The reason of this question is that at this moment, I’m developing just the new tag management. So I decided put this poll to know your opinion, as am I, uses several HMI/SCADA tools,  and that sometimes uses PascalSCADA too.

Then choose which is for you the best three tag management models that exists today, and feel free to send comments with ideas to put on the new tag management of PascalSCADA. Maybe your idea is implemented on the new version?

The best tag management model for you is...
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8 thoughts on “PascalSCADA development: What is the best tag management model?”

  1. As far as tag management, PascalSCADA is extremely straightforward. I have also done tag inventory in a manually connected tag database and then had a SCADA program run through the database (which is sort of what tags are suppose to do). Only advantage to that was sharing the database tables with a Lazarus created Email alert program and a hot hook to Apache Web server. Using the PascalSCADA tag conventions does simplify SCADA development quite a bit. -Big Thank you!

    1. This is the reason why I put the PascalSCADA model on the poll (the last choice added, a bit later). The idea of the next tool is extract the best things of the best tools. At least I’ll try 🙂

  2. Thinking in the future you can consider ISA-88 concepts like Enterprise (Project), Site, Area, Process Cells, Units, Equipment Modules and Control Modules.
    You can build a tree hierarchy, or use it partially, maybe Process cells, units and equipment modules.
    Using this object concept you can define one time and reuse those definitions to implement a complex process.

  3. I don’t know well the way pascal scada handles it, but In the past, I worked in a scada developed in Delphi 5, an our approach was very simple we had a tag table in a db and we linked tags with visual components through the component name. We loop across the components of the active form and depending of the components class of the visual component we showed the data of the tag in the suitable way. This way you keep independent the definition of tags and the interface.

    1. @Slamet it’s in development yet and it’s useless for most common tasks, like communicate with some device. The unique part that can be used is the security system (and it’s incomplete yet). Other parts are in development.

      So, still using the PascalSCADA 0.7.3.

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